While no serious injuries here make it easier to be objective about it, I think it's actually good to see one of the suspicions about self-driving cars actually borne out in real life testing: that this is an area where progression/safety isn't a smooth linear progression but more of a step function or something with a valley before rising. That means that Waymo's approach is in fact the best one: either stick to level 1, maybe a bit of level 2, or bite the bullet and go directly to 5 and figure out how to bring statistical rates there combined with the positive utility function to a point where they're flat out superior to human drivers, and
then sell that. This is actually kind of unusual for a lot of the history of tech I think, where the (not unwarranted) common wisdom tends to be more that gradual improvement and live testing and maturing over years is more effective then aiming for big leaps all at once. But there are exceptions that prove rules and this seems to be one of them: that overall safety is a combined function of human driver quality to car AI quality, but they're non-linearly inversely linked in that the more the AI takes over the more the human loses ability to stay focus and practiced, and furthermore has to deal with context shifts which are inherently slow and would inherently be required exactly when it's most serious. So it's a lot more all or nothing.
None of that should take away from the value of pursuing it however. Humans are in fact bad drivers, and have large numbers of failure modes like getting inebriated or sleepy or angry that a system can simply avoid entirely. But arguably even more important then safety, which is what tends to come up most, is utility (after all we put up with vastly less safe cars and driver practices for decades and decades before the present time already). Personal arbitrary-point-to-point mechanized transportation is effectively required for full participation in much of the modern world, it's just the danger and expense that makes it a quasi-right rather then a full one. The young and elderly being unable to take advantage is already a suboptimal state of affairs, and it's frankly a waste of everyone's valuable and limited human brain time that they're required to act as uncreative biocomputers in that role. It's all been worth it anyway because it's just that valuable, but removing a human having a required role is really just fulfilling what the tech should have been like from the beginning if our synthetic mechanical development didn't far outstrip our synthetic information collection and processing development. A certain amount of ongoing casualties and damage is entirely acceptable to achieve a societal improvement of that level of value, even if it wasn't much safer at all.